The present invention relates to a heating and pumping device for liquids, in particular for water of aquariums, of the type comprising a pump and a thermo-heating element.
Devices which consist of a pump used for circulating water, coupled to a thermo-heater allowing the water to be heated, are known. These devices can also be used in aquariums, in particular domestic ones in which it is necessary to provide a pump for circulating water in order to filter it, previously inserting a filter in the recirculating circuit; this permits also to oxygenate the water and to maintain the optimal conditions inside the aquarium for the surviving of fishes contained therein. Furthermore, for the same reason, it is necessary to maintain the water temperature between predetermined limits by a thermo-heater which depends on the type of fishes to be bred. Obviously the aquarium must contain fishes which necessitate water of the same type (salt or fresh water) which must be maintained at the same temperature.
On the market different kinds of pump exist, most of them of the centrifugaltype powered by an electric motor. Also different kinds of thermoheater exist, all of them utilizing an electric resistance for heating the water. Many improvements are made for both the pump and thermoheater, but always using these two fundamental elements.
An apparatus for pumping and filtering water for aquariums is disclosed in U.S. Pat. No. 3,635,344 filed on Aug. 21, 1970. This document concerns a pump and filter unit to be mounted on the wall of an aquarium by means of hooks. The unit comprises a housing mounted on the outside of the aquarium which contains a removable filter tank for filtering the water. A space is defined between the housing and the filter tank wherein, at the bottom, there are an electric heater for heating the water and a thermostat for controlling the water temperature. The unit also comprises a screw-type elevator mechanically connected to an electric motor placed on the top the elevator. The elevator is immersed in water so that the water is pumped into the filter tank and then it comes out from the bottom of the filter and it fills the space defined between the housing and the filter tank. The water is heated and goes into the aquarium by means of spillways made in the hooks. Producing the pump and the thermoheater separately involves high industrial costs and a long manufacturing time.
Bear in mind that these two elements in an aquarium are inconvenient and cumbersome, these troubling the field of vision, that is, they obstruct the clear visual inside the aquarium although these elements are located near the aquarium walls.
The thermo-heater has to measure the real temperature of water, hence it must not be positioned near the areas where water is prevented from circulating; therefore it is necessary to choose the right place for it that usually is near the pump.
Considering now the thermoheaters of the prior art, they generally consist of glass casing inside which an electric resistance is contained. Consequently they can be damaged because of the fragility of the material used; another drawback consists of the difficulty in providing suitable gaskets for preventing the water from penetrating inside which hinders the correct operation. This involves making suitable housing seats for the gaskets, using gaskets which allow a high degree of sealing and finally an assembly cycle to mount the whole. Finally, the temperature sensor of the thermoheater interferes with the heat which rises upwards in different ways according to the manner the thermoheater is positioned; usually the setting is made when the thermoheater is vertically positioned, therefore it is necessary to put it always in the upright position.
The aim of the invention is therefore to conceive a device which eliminates the drawbacks cited above with reference to the prior art. The device made in such way must be simple, reliable and cheap.
The aim is achieved by means of a device of the above-mentioned type comprising a pump and a thermoheater element, characterized in that said pump and said thermoheater element are contained inside a casing. The device becomes very compact, including in a sole apparatus both the function of the pump and the thermo-heater so that many advantages derive: easy to produce, quick to manufacture, troubles in the field of vision reduced to a minimum and cost lower than the sum of the individual costs of the pump and thermo-heater.
Because of the integration between the thermoheater and the pump, there is no problem in locating the thermoheater in the right position. In particular, between the thermoheater and the casing a passage section for water is defined. The thermoheater element comprises a hollow body inside which resistance means are housed, this body is integral with and in communication to the pump body which houses the statoric part of the pump in order to form a sole sealed zone.
In such a way the principle components of the device are few, so reducing the final cost of the product. Filtering means must also be placed between the thermo-heater hollow body and the casing, this means preferably consists of a cartridge in a porous material so extending the functions of the device making it more appreciable, above all, for the customers who want to reduce the total expense of an aquarium.
In order to seal the pump body with the hollow body of the thermoheater element, so forming said sealed zone, a resin is used which makes unnecessary the use of sealing elements or gaskets to prevent water from penetrating inside the thermoheater simplifying further the assembly and production phases, guaranteeing at the same time a perfect seal.